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Predicting and planning: An intelligent system for demand-based hotel staff scheduling
Get PDFThis study develops an intelligent staff scheduling system for hotels that integrates customer demand prediction with workforce planning to address contemporary challenges in hospitality management. Drawing on operational efficiency principles, the system anticipates guest demand using a long short-term memory (LSTM) network and generates optimal staff schedules by combining ant colony optimization (ACO) algorithm with variable neighborhood search (VNS) algorithm. The system is designed to balance operational efficiency with employee well-being while minimizing labor costs. Real-world testing demonstrates that the system produces schedules that outperform traditional manual methods. By automating the scheduling process, the approach aligns business objectives with employee satisfaction, resulting in more efficient operations and improved working conditions. This research contributes to the theoretical understanding of operational efficiency and its practical application in hotel staff scheduling by integrating demand forecasting with schedule planning, thereby meeting the needs of customers, managers, and employees
In safe hands: Moving the medieval archive of Durham Cathedral
No full textThis paper describes the successful completion of a large-scale collection move completed internally and collaboratively between Durham University and Durham Cathedral. It details risks and challenges, both those generally applicable to all archive collection moves and those specific to this project. Preservation was identified as the overriding priority and permeated every aspect of planning. Methods were developed for rigorously testing packaging options for shock absorption, in preparation for the expected handling and transport turbulence, and mitigations were put in place for factors beyond human control such as local weather conditions. The project capitalized on opportunities presented during the course of the move, completing a detailed stock check and making vast improvements to the existing packaging of many thousands of vulnerable items. Interdisciplinary authorship reflects the collaboration that was key to creatively overcoming challenges, leading to improvements in project efficiency and innovative use of economically and environmentally sustainable packaging approaches
Bringing memory to Boolean networks: a unifying framework
Get PDFBoolean networks are extensively applied as models of complex dynamical systems, aiming at capturing essential features related to causality and synchronicity of the state changes of components along time. Dynamics of Boolean networks result from the application of their Boolean map according to a so-called update mode, specifying the possible transitions between network configurations. In this paper, we explore update modes that possess a memory on past configurations, and provide a generic framework to define them. We show that recently introduced modes such as the most permissive and interval modes can be naturally expressed in this framework, and we propose novel update modes, the history-based, trapping, and subcube-based modes. Building on the unified definitions, we provide a comprehensive comparison of memory-based update modes, resulting in their hierarchy by simulation and weak simulation. Finally, we highlight consequences of introducing memory on the notions of trajectory and attractors
Markovian persuasion
No full textIn the classical Bayesian persuasion model, an informed player and an uninformed one engage in a static interaction. This work extends this classical model to a dynamic setting where the state of nature evolves according to a Markovian law, allowing for a more realistic representation of real‐world situations where the state of nature evolves over time. In this repeated persuasion model, an optimal disclosure strategy of the sender must balance between obtaining a high‐stage payoff and disclosing information that may have negative implications on future payoffs. We discuss optimal strategies under different discount factors and characterize when the asymptotic value achieves the maximal possible value
Ordeñándolo: episodios repetidos de lactancia tras el destete en los lobos marinos de Galápagos (Zalophus wollebaeki)
Get PDFMilk is not cheap. The energetic cost for mammalian mothers to provide and sustain milk production makes it a finite resource. Offspring are therefore expected to wean before sexual maturity and reproductive activity, whether on their own or through termination by their mothers. Weaning delays should result in a reproductive trade-off for the mother: the possibility of begetting a fitter pup at the cost of a longer interbirth interval. Using 20 years of data, we show the occurrence of repeated suckling events between female Galápagos sea lions (GSLs; Zalophus wollebaeki) and their adult (≥5 years) biological offspring well beyond the average age of independence and when the offspring are themselves already reproductively active. This behavior, “supersuckling,” suggests that GSL mother-offspring relationships are more complex and longer lasting than previously thought. To our knowledge, this is the first long-term documentation of known mother-offspring pairs repeatedly performing this behavior in any marine mammal species
How Micronutrient Status May Affect Eating Behavior-Hypothesis and Perspectives.
Get PDFThe importance of micronutrient status in human food choice remains a fundamental issue needing further investigation. The objectives of the present paper are to present and discuss historic and current research together with a general model incorporating this interaction and to suggest future research to address the questions this poses. By definition, essential nutrients must be consumed in sufficient amounts to meet an individual's requirements. While data indicate that complex neuroendocrine mechanisms provide negative-feedback control of energy and protein intake to support homeostasis, corresponding mechanisms controlling micronutrient intake are less well studied. In some contexts, they are explicitly assumed to be absent, specifically for models evaluating safety and risks of deficiencies. However, it may be hypothesized that for at least some micronutrients, mechanisms exist that aid attainment of requirements by altering preference for micronutrient-rich foods so as to increase ingestion of foods containing them, similar to how being thirsty increases the appeal of watermelon compared with dry food. If this hypothesis is correct, it may hold important implications for understanding the types and quantities of foods ingested. Greater appeal in foods richer in essential nutrients may reduce the risk of malnutrition. However, by extension, it may be posited that the use of supplements could confound the most healthful food choices. For example, obtaining vitamin C from supplements or fortified foods could then causally reduce the dietary intake of vegetables and fruits by reducing the appeal of these foods. The unintended consequence may be a lower intake of fiber, nitrate, and phytochemicals, food constituents that may contribute to health without being essential nutrients themselves. This hypothesis can and should be tested empirically, for example, through randomized placebo-controlled supplementation trials. If clear causal effects are documented, clinical and public health guidance will require critical evaluation and possible modification
Livability and non-human organisms
Get PDFIn a human changed world, many non-human organisms face a host of challenges related to their ability to migrate or remain in place. We argue for a right to a livable locality for non-human organisms further developing and applying arguments for a right to livability in the context of human climate migration. We argue that the right to a livable locality for non-human organisms emerges from the social practice of the international state system. We demonstrate that non-human organisms can be understood as a type of by-catch within the territorial net this social practice casts. Incorporating a right to a livable locality of non-human organisms into conservation practice is advantageous because it frees conservation from a dominant historical and normative evaluative scheme—in situ conservation. In a changing and warmer world, an over emphasis on in situ conservation makes conservation success difficult to achieve. A shift to livability considerations in conservation can guide normative evaluation in emergent conservation paradoxes and problems that arise due to environmental and climatic change
Dynamical disequilibrium in dwarf galaxies: rethinking gas dynamics, rotation curves, and dark matter inference
Get PDFWe quantify departures from hydrodynamical and centrifugal equilibrium in the gas discs of low-mass () galaxies from the COLIBRE cosmological hydrodynamical simulations. We evaluate the full Eulerian acceleration balance in the mid-plane and show that disequilibrium is widespread: equilibrium-based circular velocity estimates typically have errors of per cent ( per cent of mid-plane gas by mass). Disequilibrium is strongest and the largest associated errors occur in the inner few kiloparsecs that are crucial for constraining the dark matter density profile. Correcting the circular velocity to account for pressure and convective terms does not reliably improve its recovery in strongly perturbed systems where time-dependent forces dominate the residual acceleration budget. Stellar feedback, self-gravitating gas clumps, and active galactic nucleus energy injection account for most strong local perturbations, and large-scale gravitational asymmetries act as a scaffold for disequilibrium. We classify gas discs into coherent, perturbed, and slow/erratic rotators and show that this classification correlates with galaxy properties like mass, morphology, and tracers of recent feedback. A majority of galaxies in our sample would be unsuitable for standard rotation curve analysis. Much of the observed diversity in the shapes of dwarf galaxy rotation curves may stem from non-equilibrium gas motions rather than diversity in mass profiles – resolving the discrepancy is then first and foremost a problem in gas dynamics
The Onset of a Compton-thick Wind in GX 13+1
Get PDFThe X-ray Imaging and Spectroscopy Mission (XRISM) recently reported the discovery of a recurrent Compton-thick accretion disk wind from the neutron star X-ray binary GX 13+1. Many earlier observations have revealed multicomponent disk winds from this system; the wind seen by XRISM was similar but featured a column density 1 order of magnitude higher than previously reported. In this Letter, we report on Chandra High Energy Transmission Grating Spectrometer observations taken in the days prior to the XRISM observation that reveal the evolution of the Compton-thick wind. Our photoionization analysis of emission and absorption lines in the Chandra grating spectra implies the same wind geometry as XRISM and allows us to measure a characteristic timescale tw=Ṁ/M̈=2.6−1.7+5.8 days. Depending on the scattering geometry, the intrinsic luminosity inferred from our Chandra observations could be substantially super-Eddington, and we suggest that the extended period of super-Eddington luminosity is likely responsible for this massive wind
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